Definition of psychology

Psychology is the scientific study of human and animal behavior with the
object of understanding why living beings behave as they do. As almost any
science, its discoveries have practical applications. As it is a rather new
science, applications are sometimes confused with the science itself. It is
easier to distinguish what is 'pure' and 'applied' in older disciplines:
everybody can separate physics and mathematics from engineering, or anatomy
and physiology from medicine. People often confound psychology with
psychiatry, which is a branch of medicine dedicated to the cure of mental
disorders.

Some topics that 'pure' psychologists may study are: how behavior changes
with development, when a behavior is instinctive or learned, how persons
differ, and how people get into trouble. 'Applied' psychologists may use
scientific knowledge to find better ways to deal with adolescents, to teach,
to match persons with jobs, and to get people out of their troubles.
Accordingly, several branches exist of psychology: developmental psychology,
animal psychology, educational psychology, psychotherapy, industrial
psychology, psychology of personality, social psychology, are but some of
them.

Physiological psychology is a field akin to neurophysiology that studies the
relation between behavior and body systems like the nervous system and the
endocrine system. It studies which brain regions are involved in psychic
functions like memory, and activities like learning. It also studies the
complex interaction between brain and hormones that gives rise to emotions.

Animal behavior is studied by psychologists mainly in laboratory. The study
of animal behavior in their natural habitats is undertaken by the science of
ethology. The comparative study of human and animal behavior is one of the
sources of evolutionary psychology, that tries to understand how evolution
has shaped the way we think and feel.

Educational psychology concentrates on those aspects of the psychic activity
that have to do with learning. Experimenting with animals and people, it
tries to understand how they learn, and to devise better ways of teaching. A
psychological school, known as behaviorism, maintains that every human
behavior is a learned response to a stimulus, and consequently tried to
establish learning as the central topic of psychology.

The area of cognitive psychology concerns with the ways we perceive and we
express, how we store our perceptions and later recall them, and the way we
think. Perception, memory, speech, and thinking are the main subjects of this
branch. The study of decision making is a topic that has a great practical
importance.

The study of emotion and the study of personality are two related fields that
delve into the profound question of why we are different and why we feel how
we feel. While some scientists propose genetic traits as the reason, others
look to the social environment as the cause of our differences.